Good FD or Bad FD?

[mrdigitech]

I found a 750 FD for $20.

Is there any way to tell if this thing is bad?

Do they go bad?

Hope to pick it up tonight.

Thanks!

[CatatonicBug]

For $20, it's worth trying! Chances are, it's just been sitting in the guy's garage for years, and he just wants to get rid of it. They seldom go bad, but they can if they are abused.

[James England]

At $20, I'd buy it, replace the oil and check the magnetic drain plug for any large bits of metal. If none, I'd fit and run it. That's what I did with my FD which I bought off eBay. It arrived, the sump plug was OK, I fitted it and have run it since.

No doubt, under certain conditions they go 'bad' (eg low/incorrect oil.... abuse) but I'd say they are a substantial component that's designed to handle a lot of power.

I haven't got a clue what the 'lash' is on my FD or indeed any of the other technical things. IMO, if the oil that is removed doesn't show damaged components, I'd just fit it and try it........

I was out on mine tonight and I am still enthusing about the difference the FD swap has made to my bike. It's GREAT

[mrdigitech]

Great!

Thank you for the replies. Could not pick it up tonight but am tomorrow for sure because of what you all said.

Question is now do I put it on my winter project list? I'm a daily rider, 30 min therapy before and after the office, can I do without it for a period of time!?!

I'll have to re-read the process a few times to get an idea of how long this could take.

Or I could just park it for a weekend and do a few things.

Thanks again!
Dren

[CatatonicBug]

Takes about as long as a full fluid change, if you have all the stuff prepared beforehand. Cut the spacer, and get that washer and RTV ready and have gear oil and grease ready to go, and it doesn't take long at all. Be sure to check the fluid level in the new FD with a dip stick before you ride though. Somehow, I overfilled mine even though I was sure I used the right amount.

[James England]

I certainly wouldn't wait until winter! It's not one of those sort of jobs.

As said already, cut your spacer first. The rest of the job takes no more than a couple of hours. I would remove the seat etc, raise the rear fender, remove the rear wheel, then remove the shocks and tie the swinging arm up with a piece of thin rope. This allows you to get at the four nuts that hold the FD on more easily. I would do this even though I have the cable puller thing to raise the swinging arm ( I always imagine the cable slipping or snapping....)

I wanted to double-check the torque on the pinion nut on mine because there are two types of 750 FD. They have a different torque on the pinion nut and I'd tightened my nut to the Type II setting instead of Type I. I discovered this next day (from the forum). I removed the FD, re-torqued and re-fitted in 40 minutes, so it's not at all difficult.

Check your 750FD when you get it. There are two types and this is not so clear in the tech tip. One has a countersunk screw in the flange that bolts onto the swinging arm and I believe it has a crush washer, not a normal washer. The other doesn't. You have to remove the pinion nut and replace the washer and block the spooge holes (as per tech tip) and this means you need to re-torque the pinion nut when you put it back on. This is an important step because you are pre-loading a conical roller bearing on the inside of the FD. The two torques are very different. When mine was too tight, the FD was hard to turn. Too loose and you get what happened to 3-Phase (I think it was you, Scott?) and the bearing gets damaged. I used a torque wrench and, after the correct torque, I turned the drive and compared it to the OEM one. They felt the same to turn, so I thought that was good enough.

I would get your FD, establish what type it is and then put a post on here asking what the torque should be. Yes, I know it'll be in the threads somewhere, everyone, but we all love responding to questions don't we? And it can be a very long process trawling through all the posts, I find.

I'm going out on mine in about half an hour (09:00am here) and can't wait. The FD conversion is just so good. Yesterday, at about 55mph, I'd 'forgotten' I'd put the FD on, thought to myself "I wish this bike had a 6th gear" (as usual) and was delighted to find I hadn't changed into 5th! I changed and the usual stressed (to my ear, anyway) sound of the engine changed to a comfortable, happy purr. I've done 400 miles on it so far with no problems, by the way...

[CatatonicBug]

XS850 FD's are the same as well, and AFAIK, there is only one kind of those. I may be wrong on that though...

[petejw]

with out pulling it apart and checking the internals,
as long as the output shaft turns smoothly, without
any notchiness, u should be sweet to go and as the others
have said, u cant go to wrong for $20.00.